Recognize bridging faces of splits at a plane
One not always working way is to select similar vertices by amount of connected edges with increasing selection after that.


Start by selecting one vertex located in the corner between one of those "bridged faces" and main plane.
Press Shift+G to access Select Similar menu and choose Amount of connected edges. This will select some of vertices of desired part.
Increase selection by pressing Ctrl+Numpad + to select more.
Switch to Face Selection mode and decrease selection by pressing Ctrl+Numpad -.




This won't work when part of plane between these "bridged faces" is less than 4 polygons. Then on step 3 you'll end up with more selected faces you could deselect in step 4; i.e. the deselection won't work that accurate.